Not applicable.
Not Applicable.
The present invention relates generally to fire prevention and in particular to improvements in appliances in order to prevent or arrest fires starting as a result of the operation of the appliances. Fires that occur in homes can be started by a number of factors. One of the causes of household fires is a malfunctioning clothes dryer, and the U.S. Consumer Product Safety Commission has estimated that clothes dryers cause more than 15,000 fires each year. Most dryers operate on electricity and draw significant amounts of electrical current to produce the heat needed for drying the clothes and for rotating the drying drum, while other dryers use gas to provide the heat. In each case, most dryers have an internal safety mechanism that will interrupt the power to the heating elements in case of a malfunction of the heating elements. Unfortunately, some fires will not be prevented or controlled by these internal safety mechanisms alone. For example, a fire could damage the mechanism before it can become activated, and, even if activated, the interruption of power alone may not be enough to prevent or control the fire. Finally, an internal safety mechanism alone generally does nothing to alert the dryer operator or others of the presence of a fire. An example of a fire protection device that can be used with a clothes dryer is described in the patent to George (U.S. Pat. No. 4,930,579). This patent describes an automatic sprinkler head system that, when activated, sprays water over the entire area in which it is located, which may cause a significant amount of water damage to that area. Other examples of clothes dryers that incorporate fire protection are disclosed in the patents to Smith (U.S. Pat. Nos. 5,396,715 and 5,606,804). These patents, however, are primarily directed for use with a microwave dryer, and, arguably, include a complicated monitoring system and water as the extinguishing agent, which may not be practical for use with many of the conventional gas or electric dryers already in service. Therefore, a need still remains for a relatively simple device that can arrest or extinguish a fire, remove the usual source of heat, and alert the user and others of a dryer fire.
According to its major aspects and briefly recited, the present invention is an improvement to clothes dryers that may stop a fire before it has developed into a conflagration and, in an alternative optional embodiment, put the fire out and provide a remote alarm. The invention includes a fire detector at the dryer exhaust that shuts down the dryer after detecting the presence of a fire, and, in an alternative embodiment, the fire detector signal is also used to release an extinguishing medium into the air intake or into the internal volume of the dryer itself to suffocate the fire, and/or to reduce the temperature of the environment below the temperature needed to sustain combustion of the source of fuel for the fire. Another alternative embodiment includes additional alarm features that are also activated by the fire detector.
An important feature of the invention is the use of a fire or smoke detector to control the operation of a malfunctioning dryer including, but not necessarily limited to, assuring that the malfunctioning dryer is shut down. An advantage of this feature is that it allows for the removal of the electrical power and/or the supply of gas to the heat source while also possibly providing for the possibility of allowing the blower/fan to continue operating so that an extinguishing medium can be pulled through the dryer.
Another important feature of the present invention is the combination of a fire extinguishing means, such as carbon dioxide or other suitable extinguishing media, and a fire or smoke detector, to both detect and put out a fire in a dryer or other appliance.
Another important feature of the present invention is the use of an alarm to notify the local user of the dryer of the existence or possibility of a fire, and/or to provide remote notification to others, for example, to an alarm-monitoring service.